Why we need to build the Grimsby to Walpole upgrade

Much of the existing high voltage electricity transmission network was built in the 1960s and does not extend into large parts of Lincolnshire. With the growth in power flows on the network from increasing offshore wind and interconnectors, the amount of electricity landing on the east coast and flowing through the Lincolnshire region by the end of this decade will be more than the existing network can currently accommodate.

There are currently four double circuit 400 kV overhead lines and a couple of lower voltage 275 kV overhead lines carrying power from Scotland and the North of England into the Midlands and beyond.  Together those existing circuits can carry around 11.6 GW of electricity whilst remaining compliant with the standards to which the network is operated. National Grid ESO in the latest Electricity Ten Year Statement anticipate that the network between the North and Midlands needs to transfer as much as 29 GW of electricity by 2033.

In the first half of this decade, we will be carrying out works to deliver more capability from the existing network. Those works, which involve upgrading existing overhead lines, will only increase the capability of the network to transport around 14 GW of electricity between the North and the Midlands. We therefore need to build new lines, including Grimsby to Walpole.